The present disclosure herein relates to semiconductor memory devices, and more particularly, to nonvolatile memory devices.
Semiconductor memory devices are memory devices that are implemented using a semiconductor, such as silicon. The semiconductor memory devices are classified into volatile memory devices and nonvolatile memory devices.
Volatile memory devices lose data stored therein when power supply thereto is interrupted. Examples of volatile memory devices include static random access memory (SRAM) devices, dynamic random access memory (DRAM) devices, and synchronous dynamic random access memory (SDRAM) devices. Nonvolatile memory devices retain data stored therein even when power supply thereto is interrupted. Examples of nonvolatile memory devices include read-only memory (ROM) devices, programmable read-only memory (PROM) devices, erasable programmable read-only memory (EPROM) devices, electrically erasable programmable read-only memory (EEPROM) devices, flash memory devices, phase-change random access memory (PRAM) devices, magnetic random access memory (MRAM) devices, resistive random access memory (RRAM) devices, and ferroelectric random access memory (FRAM) devices. The flash memory devices are classified into NOR-type flash memory devices and NAND-type flash memory devices.